Camera technology and gesture recognition technology have experienced phenomenal growth in the last few years. Game devices have adopted such technologies. For example, a game device may recognize a gesture of a player using a camera and use the recognized gesture of the player as an input signal for playing a game. Game software developers have developed various types of gesture-based games for such game devices. Players can play the gesture-based games using their gestures (without using a keypad-type input device). However, multiple players of a gesture-based game may be adjacent to each other and may collide with each other while playing the game.